Chilli Veinal Mottle Potyvirus (ChiVMV ) penyebab penyakit belang pada cabai (capsicum annuum l.): keragaman isolat dan strategi pengendaliannya melalui induksi variasi somaklonal

Abstract

Chilli veinal mottle potyvirus (ChiVMV) is one of important viruses infecting chilli pepper plant. It was reported that ChiVMV infection may cause 50% to 100% yield losses. The virus has a very wide host range and strain diversity. The aim of this research are to characterize biological variation of ChiVMV and to obtain plant resistance source via somaclonal variation through induced mutation. Six isolates of ChiVMV was collected from different geographical region of chilli pepper production area. Based on their infection on 10 genotypes of chilli pepper, it was indicated that they have differences in virulence level and symptom type. Isolate collected from Cikabayan, Bogor, Jawa Barat (ChiVMV CKB) was able to infect all 10 genotypes with severe symptoms showing mottle, vein banding, leaf cramping and malformation. Analysis of coat protein gene indicated that ChiVMV isolates collected in this study can be differentiated into 3 groups although they have close relationship with other strains of ChiVMV published earlier in GeneBank. However, further analysis of amino acid revealed that ChiVMV CKB has different motif of octapeptide compared to other strains. The most virulent strain, ChiVMV CKB, was used for evaluation of somaclonal plants produced by in vitro propagation combined with induced mutation using EMS. Twenty somaclonal plants showed resistant response to ChiVMV infection and potential to be used as genetic resources to develop resistant plant.

Chilli veinal mottle potyvirus adalah salah satu virus utama yang menyerang tanaman cabai. Walaupun keberadaannya di Indonesia tergolong baru, namun penyebarannya dapat ditemukan hampir disetiap pertanaman cabai. Infeksi ChiVMV dapat mengakibatkan penurunan hasil 50% hingga 100%. Untuk mengatasi terjadinya ledakan penyakit, menggunakan varietas yang tahan terhadap virus merupakan salah satu alternatif. Namun sampai saat ini belum diperoleh varietas cabai tahan ChiVMV. Bila sumber gen ketahanan terhadap virus masih terbatas, maka salah satu upaya peningkatan sumber gen ketahanan tersebut dapat dilakukan melalui induksi keragaman somaklonal yang dikombinasi dengan induksi mutasi.